Posted by troglo-byte 12/22/2025
That's not the case here, that center is __dumping__ heat into environment - it is by design, all that electricity is being converted into the heat. By design, it's enormous electric heater.
If you pull 100W of power out of an electric socket, you are heating your environment at 100W of power completely independent of what you use that electricity for.
"British reversible computing startup Vaire has demonstrated an adiabatic reversible computing system with net energy recovery"
https://www.eetimes.com/vaire-demos-energy-recovery-with-rev...
Short introduction video to reversible computing:
Thanks for posting. Pretty cool.
On a related/side note, when there's talk about seti and dyson spheres, and detecting them via infrared waste heat, I also don't understand that. Such an alien civilization is seemingly capable of building massive space structures/projects, but then lets the waste heat just pour out into the universe in such insane quantities that we could see it tens/hundreds of light years away? What a waste. Why wouldn't they recover that heat and make use of it instead? And repeat the recovering until the final waste output is too small to bother recovering, at which point we would no longer be able to detect it.
There is no way to get rid of heat. It has to go somewhere; otherwise, the temperature of the system will increase without bound.
Or if you magically beam 100% of the captured energy somewhere else, now that place gets to deal with shedding the heat from however many 1e26W+ of power were consumed. God help the poor planet you aim that ray of death at.
There is no other alternative! If I build a perfect Dyson sphere and capture the energy output of a star, all of that energy will become heat. The average surface temperature of my Dyson sphere will be (IIRC) the ratio of the surface area of the sphere to that of the contained star, multiplied by the star's effective surface temperature.
"Recovering heat and making use of it" requires a heat differential. You need a cold side and a hot side to use energy. Using that energy causes the cold side to heat and the hot side to cool, until they reach equilibrium. The further the difference, the more usable work you can do. The closer the two sides are, the less work you can do.
Someone else here said it best: waste heat is the graveyard of energy. Once you have used energy, it will become high-entropy, low-grade, diffuse heat which is difficult-to-impossible to extract further work from.
Yes it ends up as heat, but with some forethought, it could be used to eg heat people's homes rather than as waste.
In really, it’s not convenient to move all waste heat to where it’s more needed.
The energy of the universe is a pool of water a top a cliff. Water running off this cliff is used to do stuff (work), and the pool at the bottom is heat.
The "heat death of the universe" is referring to this water fall running dry, and all the energy being in this useless pool of "heat".
Is it impossible to convert heat into other forms of energy without "consuming" materials like in the case of steam, geothermal or even the ones that need a cold body to utilize thermoelectric effect.
[1]: Technically the movement itself is heat, the objects don't contain heat, rather they contain internal energy, but the two get mixed up more often than not.
And that’s ignoring that sound and photon emissions typically hit a wall or other physical surface and get converted back to heat.
It all ends up as heat in the end, just depends on where that heat is dumped and if you need to cool it or not. Most watts end up being even more than the theoretical heat per watt due to said cooling needs.
There is literally no way around the fact that every watt you burn for compute ends up as a watt of waste heat. The only factor you can control is how many units of compute you can achieve with that same watt.
That reminds me of a sci-fi book, Sundiver by David Brin, where a ship is exploring the sun by firing a "refrigerator laser" to somehow pump-away excess heat and balance on the thrust.
I say "ordinary computers" because other comments mentioned "reversible computers" for which this limit doesn't apply.
According to the linked wikipedia page, this theoretical limit is around a billion times smaller than current computers use for an operation, so you may call me pedantic.
Certain chemical reaction endotermic reaction require energy to start. This energy is absorbed to generate molecular bond.
Also in the generation and absorption of high energy radiation there are non-thermal processes that can transfer energy.
Even something like bending a metal bar is not 100% a thermal process.
After removing power even that small amount ends up as heat through friction ( both in the bearing but mostly in the air turbulence). And the blades end up in the same zero energy state: sitting still.
So it is correct that a 100% "end up" as heat
We do know what that air does eventually. Given no further inputs of energy, it swirls around generating friction, raising its temperature (heat!) as the currents slow down to nearly nothing.
And it only cost 0.006 rain forests!
For example, kinda wasteful to cook eggs with new electrons when you could use the computer heat to help you denature those proteins. Or just put the heat in human living spaces.
(Putting aside how practical that actually is... Which it isn't)
It's that computation requires electricity. And almost all of the heat in bitcoin mining comes from computation, technically changing transistor state.
It would be wonderful if we could capture that waste heat and give it a useful purpose, like heating homes, or perhaps even generating new electricity.
(And this is before getting into the fact that I believe mining cryptocurrency is a wasteful use of electricity in the first place.)
Computational results do not contain stored potential energy. There is no such thing as energy being "used up" doing computation such that it doesn't end as waste heat.
Even if turned into useful work, the end result of that work is still ultimately heat.
We can generate less heat per computation but it eventually cannot be avoided.
I guess, if it's using fossil fuel to generate power it's also just moving heat from one place to another, but really really slowly. The relevant factor there is that the long term storage was performing a important secondary function of holding a lot of co2.
It's in Texas, surely that's an area amenable to solar production. What are they actually using there.
You're right, it's not leaking, it's dumping excess heat on purpose.
However, I get triggered whenever someone uses the term "by design" wrongly. The generation of heat is not by design. It's an undesired side-effect of the computing being done. "By design" would mean that someone decided that there should be a certain amount of heat generation and made sure that it happens.
Most often I see this term misuse from developers who explain bugs as being "by design". It happens when two features interact in an undesired way that creates problems (a bug). Developers like to look at feature A in isolation, determine that it works as designed, then look at feature B, determine that it also works as designed, then they look at and understand the interaction between feature A and B and since they now understand what is happening, they claim it's "by design". However, nobody ever decided that feature A and B should interact this way. It was clearly an oversight and every normal person would agree that the interaction is undesired and a bug. But the developer says "won't fix, this is by design". Infuriating!
Edit: One steel foundry uses about 3,000 more than that, according to my napkin math
Is this a daily usage thing? I test based on my home usage and the numbers seem way out. I use about 25kWh per day.
I have a smaller house, we use about 13kWh per day. 4kw highest spike during the day around 5-7pm when people are cooking and doing laundry.
Your usage is very low. Do you use electricity for water heating and cooking? If so, that’s impressive.
We do, and charge a car.
Used to have one electric car but it was on a separate meter with unlimited charging for $40/mo (just looked, now its $46). Added a few hundred to the charger install originally.
We really don't do too much around the house. Three people. One TV running maybe two sometimes. Two desktops (well one is laptop with a dock). A random PC as a server. Everything electric (oven, range, water heater, filtration, etc) besides furnace (nat gas), although I will say they are all new and pretty energy efficient. Random lights (all LED, Hue). Someone turns on an electric heater or blanket here or there. Some outside heated cat house and water heaters and stuff. In Michigan so its pretty cold right now.
I recently bought a bunch of (used) solar panels and was doing our load calculations for peak draw and selecting battery size.
How much of your usage is the car? I could imagine that would be a lot. A single model 3 refill (57kwh) would be almost 5 days of my usage.
edit: I'm dumb. We replaced our electric water heater a few months ago with a tankless gas. I don't feel like rewriting this reply but just keep in mind.
I would eventually like to replace the furnace and the water heater with electric so I can end gas service to my house. I do feel its the safest and in the future we will be looked back on as backwards. "They used to pump a flammable gas directly into their houses!"
With solar we are making a ton more power than we are using at the moment, it’s a sunny summer and we are managing to export something like 8x the power we are drawing from the grid.
I recently bought 30 600w panels that were used, apparently they used to be on a GM parking lot canopy but got uninstalled during covid lockdown and were in storage for ~4 years. I got a great price and I've tested ~30% and they are all in spec.
We pay ~$0.23 per kwh all in (supply, distribution, etc). Our provider (DTE) only pays ~$0.08 per kwh we supply, and its a credit and maxed out at our bill amount. So if we spend $200 on energy, we can only get $200 off. Which does mean free electricity, but also means no profit.
We use about ~1000kwh a month, our 30 panels can generate about ~3000kwh a month. Could deploy just 10 panels and resell or do better with batteries but the resell market does not make sense for me.
Last month it was 7. And we’re in the winter. Over the summer is more like 5.
Arc furnace foundry : 500 kw/tonne
Production : 150 t/hr
500*150 = 75 MW/h
So it's a useful figure if you want to make a shocking headline. "Uses as much power as infinity of something that uses no power!"
As in, we have now have the energy capacity for 300,000 fewer homes given this operating data center.
So not only is it a relatable unit, but it's an incredibly meaningful unit for those who care about ensuring that energy availability actually support something of value (families) rather than something wasteful (crypto mining).
Folks should be happy since the crypto operation is using far less power and dumping less heat into the environment that the industrial operation that was previously there, but datacenters seem to be a trendy thing complain about at the moment so here we are.
It's burning less power than before, but it's not producing anything of value.
The world cannot reasonbly run without alu, it got along better without crypto currencies.
I remember the local press going on about the crypto mining operation and how folks were going get high-tech jobs in this rural area of Texas. Of course it didn't go that way.
Aluminum smelting is an incredibly energy intensive operation. A lot of places in the US that used to host aluminum smelters now host large datacenters, include the Google data center in The Dalles, Oregon on the Columbia river near a hydro dam. It's a shame that Rockdale didn't get something useful like these other places.
As far as Al smelting in the US; I don't know. I'd imagine it produces a lot of air pollution by itself and uses huge amounts of power that is usually generated by cheap methods like burning rocks (coal) or large hydro operations nearby to minimize transmission costs. Then you gotta get ore to the site. The only Al smelter I recall being left in the US is up near Puget Sound in Bellingham, WA and I think it's currently shutdown.
Relatively speaking, bauxite is practically worthless. But mix it in with a few gigawatt hours and you get out a fairly valuable commodity.
That's a disappointingly common crypto industry lie. Cryptocurrency mining involves very little labor beyond initial construction; it's certainly not a major source of permanent employment.
It remains to be seen if AI will end up being about as useful as crypto in the long run.
The smelter was providing jobs that fed money into the local economy. I'm sure much less money is coming out of the mining operation.
It would be cool if all this residual heat could be concentrated to smelt aluminum!
Why does this even exist?
And yes, I get what mining is and I get what the blockchain does. I’m saying that proof of work is absurd.
Welcome to our cashless society. It’s naive to think no one would fight back.
It may have devolved to useless speculation and gambling for now, but the genie cannot be put back into the bottle very easily at this point.
We've been able to talk to machines, have them understand that speech, and do work based on it, for decades. But we're all still typing into keyboards.
We've had devices which can track our eyes to move a mouse pointer for 37 years, but we all still use our hands/thumbs to move a mouse.
We had mobile devices which had dedicated keys for input which allowed us to input without looking, and we replaced those with mobile devices with no dedicated keys (so we have to look to provide input) and bodies made of glass so they would shatter when dropped and required additional plastic coverings to protect them. Even automobiles, where safety is a high priority, also adopted input devices which require looking away from the road.
Our world includes a government which is indented to be led via decisions from all the people, and could easily be overthrown by all the people, but only a select few people actually get to make decisions, and they don't have to listen to the people, and basically do whatever they want (wrt the other few people who get to make decisions).
Yes, life is needlessly absurd. It's best not to think about it unless you wanna end up in a padded room.
Humans produce about 20TW globally at this time (ChatGPT), while the sun adds about 174000TW of energy to the earth.
I guess you could argue that our waste heat does something, but I think the greenhouse gases that trap this enormous energy more effectively have a far bigger effect.
We use a fraction of the sun’s total energy output each year, orders of magnitude more energy are in sunlight radiating onto the Earth than in the heat rejected from buildings with air conditioning.
Estimated energy production from all combustion and nuclear from the industrial revolution onwards, assumed that heat was dumped into the atmosphere evenly at once, calculate temperature rise based on atmosphere makeup. Ignores the impact of some of that heat getting sinked into the ground and ocean, and the increased thermal radiation out to space over that period. In general, heat flows from the ground and ocean into the atmosphere instead of the other way around, and the rise in thermal radiation isn't that large.
On the other hand, this isn't something that the smart professionals ever talk about when discussing climate change, so I'm sure that the napkin math working out so close to explaining the whole effect has to be missing something.
We use ~20 TW, while solar radiation is ~500 PW and just the heating from global warming alone is 460TW (that is, how much heat is being accumulated as increased Earth temperature).
The amount of heat rejected to the atmosphere from electronic devices is negligible.
They're pretty much adjacent, but the orientation of the buildings is different:
https://www.google.com/maps/place//@30.5678809,-97.0740152,2...
You want to read about "conservation of etendue" for a technical explanation. For an easier explanation, look for xkcd's excellent "Fire from Moonlight".